Relative nutritional deprivation was produced in groups of 16 to 21 newborn rats who were all nursed by one dam (deprived group) and compared with control litters containing 10 or less animals. Both groups were weaned at 21 days and thereafter allowed an unlimited supply of food.
There was diminished somatic growth in all of the deprived group and, at 2 and 3 weeks, the weight of many of the deprived animals was approximately one-half that of the controls. Brain weight, total brain lipids, cholesterol, and phospholipids were reduced to approximately 80% of the control. Brain cerebrosides were affected to a greater extent than the other lipids, being only 50% of the control values. Histological sections showed less myelin. At 6 weeks, following 3 weeks of ad lib. food intake, the body weight, brain weight, and concentrations of the brain lipids of the initially deprived animals were essentially equal to those in the control animals.